A night-time OLS (Operational Linescan System) visible± near-infrared (VNIR) channel image of the DMSP (Defense Meteorological Satellite Program) was overlaid on the simultaneously corrected OLS thermal infrared (TIR) channel image for the area around Japan. The OLS composite image showed a clear relationship between the location of ® shing¯eet lights detected by the VNIR channel and the sea surface temperature (SST) distribution observed by the TIR channel. Many ® shing¯eets were located at the cold side of the boundary area between warm currents and cold currents. Since some types of ® sh are likely to gather in certain sea temperature zones, the OLS composite image may provide useful information for the monitoring of ® shing¯eets as well as for marine resources management.